Domain age & quantity/breadth of content should be taken into account in ranking.
A fresh domain that suddenly has a ton of content should be viewed with suspicion and downranked as it's likely a spammer (copying GitHub/Stackoverflow/official docs).
Legitimate sites that are starting out shouldn't be affected as they are unlikely to have a ton of content from the start.
Of course, this isn't perfect, but it should take care of the majority of spam copycat sites.
You think all the existing search engineers haven't thought of using the domain age for the signal and tried it yet? And if you did, you think SEO people wouldn't figure it out and take advantage of it? This cycle of adversarial game on this particular signal has already gone through the full cycle - https://www.searchenginejournal.com/ranking-factors/domain-a...
And what makes you think search engines don't take quantity and breadth of content ? And, why do you think SEO won't be able to take advantage of that ?
Most people commenting and lamenting about search quality need to understand how much of search quality is an adversarial game, that neither side (search engine vs SEO people who want to manipulate the result in their favor) can win decisively forever. And generally it's not for the lack of trying the quality hasn't improved as much - it's just some areas it's more difficult to make progress due to more money spent on making it difficult for the search engines.
What I am most disappointed about Google and search engines in general isn't so much about ranking simplistic things like generic recipe or product reviews and stuff like that - most recipes for general items are all similar, and product review is inherently commercial that reviews always have been biases (short of using Consumer Reports, almost all magazine review articles are biases and influenced by manufacturers). What I am most disappointed is the lack of improvements in UI and retrieval/recall. Interactive UI that can narrow down search space iteratively and interactively so that I can describe what I want in more precise way is lacking. Where is the virtual librarian that I can talk to to narrow down what I want in a step by step way ? Instead of a single search query being the only input, why shouldn't search engine ask for clarifications and let users more precisely describe what they want ? Human languages and human brain just don't produce a single phrase to describe what we want - it takes sentences and questioning back and forth to determine what we want, and we often need more input to realize and describe what we actually want. And all search engines have failed to provide such an interface. And my bet is that whoever can crack that would beat all other search engines, since users can give better, higher quality input for the search to find.
A fresh domain that suddenly has a ton of content should be viewed with suspicion and downranked as it's likely a spammer (copying GitHub/Stackoverflow/official docs).
Legitimate sites that are starting out shouldn't be affected as they are unlikely to have a ton of content from the start.
Of course, this isn't perfect, but it should take care of the majority of spam copycat sites.